defrec_dfs(G,s,S=None):ifSisNone:S =set() S.add(s)foruinG[s]:ifuinS:coontinue rec_dfs(G,u,S) 迭代版的深度优先搜索 : defiter_dfs(G,s): S,Q=set(),[] Q.append(s)whileQ: u=Q.pop()ifuinS:continueS.add(u) Q.extend(G[u])yielduif__name__=="__main__": a, b, ...
一. 知识点介绍 深度优先搜索DFS:类似于二叉树的先根遍历 广度优先搜索BFS:类似于二叉树的层次遍历 二.算法实现 广度优先遍历(BFS) 1.策略:从起点开始,遍历其邻接的节点,由此不断向外扩散 2.步骤: 如图所示,我们可以看到如果从上输入5*5的迷宫矩阵的右下角点A(0,0)出发,假设终点为点o(3,5),且合法走法...
检查排序是否完成 defcheck(li, reverse=False):ifreverse ==False:foriinrange(len(li) -1):ifli[i] > li[i +1]:returnFalseelse:returnTrueelifreverse ==True:foriinrange(len(li) -1):ifli[i] < li[i +1]:returnFalseelse:returnTrue 冒泡排序 # 冒泡排序importrandomdefbubble_sort(li:list)...
*/ public List<Integer> postorderTraversal(TreeNode root) { List<Integer> res = new ArrayList<>(); Stack<TreeNode> stack = new Stack<>(); if (root == null) { return res; } TreeNode cur = root; TreeNode pre = null; stack.push(root); while (!stack.isEmpty()) { cur = stack...
# to print DFS traversal self.DFSUtil(v, visited) # Driver code # Create a graph given # in the above diagram g = Graph() g.addEdge(0, 1) g.addEdge(0, 2) g.addEdge(1, 2) g.addEdge(2, 0) g.addEdge(2, 3) g.addEdge(3, 3) ...
from collections import dequedef level_order_traversal(root): if not root: return [] result = [] queue = deque([root]) while queue: level_size = len(queue) current_level = [] for _ in range(level_size): node = queue.popleft() current_level.append(node.val) if node.left: queue....
self.dfs(root,[]) #深搜回溯 return self.res def dfs(self,root,path): #回溯方法 if root is None: return self.ass[root.val]+=1 #将节点数值对应的数字个数加1 if root.left is None and root.right is None:#当达到叶子节点时开始判断是否为伪回文 x=0 for i in range(10): if self....
def dfs(i: int) -> int: if i <= 1: return 1 return dfs(i-1) + dfs(i-2) return dfs(n) # 递推 class Solution: def climbStairs(self, n: int) -> int: fo = f1 = 1 for _ in range(2, n+1): new_f = f1 + f0 ...
Directory traversal tools in Python, Directory traversal tools in Python. os.walk () method of the OS module can be used for listing out all the directories. This method basically generates the file names in the directory tree either top-down or bottom-up. For each directory in the tree ro...
LintCode 902. 二叉搜索树的第 k 大元素 代码模板 Java List<TreeNode> inorderTraversal(TreeNode root) { List<TreeNode> inorder = new ArrayList<>(); if (root == null) { return inorder; } // 创建一个 dummy node, 右指针指向 root // 放到 stack 里,此时栈顶 dummy 就是 iterator ...